Growing Up
by phantomworks
Summary: Joey accidentally drank an experiment that Kaiba had put in the refrigerator and has been transformed into a kid. Now the brunette is stuck taking care of him. Where will this disaster lead?  my first Puppyshipping, please don't make fun of me!
1. Chapter 1

Phantomworks: okay, this is my first try at puzzle shipping, but I got this idea by reading a story of Reibar-Ookami's.

**Alice; but you aren't ripping it off from her?**

Phantomworks: no, this has changed so much that I think I can call it my own creation… but just in case, I got permission to write it.

**Alice; good. Cause I like Reibar-Ookami's work.**

Phantomworks; me too! Did you read the one about-?

**Alice; let's talk about this later and just start the story.**

Phantomworks; oh, right. I don't own Yugioh or its characters, only this fanfic. Please enjoy.

Chapter 1

"Seto! Stop working! You need a break!" a high-pitched voice pounded on the door of his room. Blue eyes glared at said piece of wood with a vengeance.

"I'm busy Mokuba! This has to be done by tomorrow!" he yelled back as he carefully poured a bubbling purplish solution into a glowing green one. If by tomorrow you mean three months, then yes. The brunette had to turn it in 'tomorrow'.

"Seto! You know as well as I do that your work is covered for the next three months. Unless something happens in the next twenty-four hours, you have nothing worth doing immediately." Mokuba called back through the door. "If you don't come out here right now, I'm calling Yugi and inviting him and his friends over." the small pre-teen warned. After hearing no response, he sighed and walked off, flipping out his cell phone.

"Hey Yugi?" Mokuba greeted his friend, "Yeah, he said it's okay, so when are you coming?"

~with Seto~

"Finally! The truth serum is complete… almost. I need to let the solution cool." Seto mumbled to himself as he carried the clear brown bubbling liquid to his giant refrigerator. He poured it into a thinner material than glass –a tin soda can and closed the frig door.

"Now I only have to wait for it to-!" Seto stopped dead in his tracks when he happened to glance into his front hall. Was he seeing things? Blinking, Seto rubbed his eyes. No, his mind wasn't playing tricks on him.

Yugi, his arch rival, was standing right in front of his door. The teen was drying his hair with a towel just as his 'other self' ran in from the rain storm outside. And who else was there?

Joey Wheeler, second rate duelist.

"What is going on here?" growling, Seto stormed up to the small group. His little brother looked up at him innocently.

"I told you I was inviting Yugi and his friends over." Mokuba said simply.

"I heard nothing of the sort, nor did I agree to this!" Seto crossed his arms and stood his ground menacingly.

"I told you while you were still 'working'. No reply came back so I took it as the go ahead. Remember – silence is compliance!" the younger sang as he opened the door for Ryou, Bakura, Tristan and Duke.

The older glared at the group, but let it go, turning and walked away. His little brother was good. Perhaps he was training him a little _too_ well? Slipping into his office, he sat down to work for the next couple of hours.

"Hey guys, want something to drink?" Mokuba asked. Yugi and his friends were staying longer than expected because of the bad weather. Duke and Tristan had managed to get to the dice dueler's car and drove off when the time came, but the others were stuck where they were.

Which was a much better choice for Joey. Anything to get away from his dad for a couple hours.

"Sure! I'll take coke!" Joey grinned.

"Me too!" Yugi piped up.

"No, you get Sprite. No caffeine for you, Aibou." Yami said. "I'll have Sprite as well."

"Can I have some tea?" Ryou asked timidly. Mokuba nodded, already running over the list in his head again.

"Bakura? Anything for you?" Mokuba asked politely. The white spirit turned to him slowly with a maniacal grin.

"Got beer?" he asked. Sighing, Mokuba crossed his arms.

"I'm sorry, we're fresh out. Anything _else_?" total sarcasm filled his voice. Grumbling, the white demon shook his head.

"Nah, I'll get something later." His eyes slid to his little double. The younger blushed a brilliant red and hid his face with his bangs. Mokuba really hated it when the others said an inside joke he didn't get while he was around. Turning, he left the living room, nearly running into his older brother.

"Hey, Seto! Have you decided to join us?" Mokuba asked, hopeful. His brother shook his head.

"I need to get a few things and I'll be right back to work." Seto walked off with that.

Shrugging, Mokuba quickly made his way to the kitchen. After putting water on to boil for tea, he quickly found the two Sprites for the tri-color haired duo, but couldn't for the life of him find coke. There was absolutely no coke!

Pouting, Mokuba's eyes alit on a silver can. "Hope Joey likes coke zero." He said. After pouring the tea and popping the tabs on the cans, he rushed the drinks back to his friends.

"Here you go!" he sang, handing out the drinks.

"Thanks Mokuba!" Joey said, taking a big gulp of his can.

"Yummy!" Yugi sipped his with an appreciative sound. "Did you get anything for yourself, Mokuba?"

"Oh! I forgot! I'll be right back." Sprinting off, the small boy didn't even notice his brother walk in.

"Hey Mokuba have you-? Where's Mokuba?" Seto asked, not seeing his brother in the room.

"He went to get a soda for himself." Ryou answered.

"What are you all still doing here?" blue eyes narrowed.

"If ya haven't noticed, it's rainin' cats and dogs out dere. Ya expect us ta go out in dat?" Joey growled. Yugi put a restraining hand on Joey's arm.

"Can we help you with something, Kaiba? You came in here looking for something, tight?" amethyst eyes looked up questioningly. Joey took a long drink of his strange tasting coke.

"I don't think that you could help at all. You see I'm looking for-!" Seto's eyes alighted on Joey's drink.

"What are you drinking, Wheeler?"

The blonde swallowed and looked at the can, "I'm not sure. Mokuba gave dis ta me an' I thought it was coke zero, but it tastes funny."

"You drank it?" Seto exclaimed, swiping the can from the blonde's hand. Shaking it experimentally, he realized with sudden anger that it was empty, "all of it?"

"Um, y-yeah? Why? What's it to ya?" Joey flinched from the sudden glare he got from the tall brunette. Seto grabbed Joey's shirt collar, forcing the smaller to stand on his toes.

"This was an experimental truth serum and you. Drank. It!" Seto growled, punctuation each word with a harsh shake.

"Kaiba! Please calm down!" Yugi managed to get the brunette to release his friend with Yami's help. "Now, tell us, what do you mean experimental?"

Taking a slow deep breath, Kaiba started, "my company deals a few military products as well as games for the populace. Recently, the military has wanted to make a truth serum. However, this was only a proto-type! It's still in the testing phase!"

"What? Oh no!" Yugi's eyes darted to Joey then back to Seto. "What's going to happen?"

"I don't know. It hasn't been tested, let alone on hum-"

"Guys? I feel funny." Joey interrupted. Everyone turned to look at him and gasped. His skin was glowing a golden color and a mysterious air was levitating his clothes and hair.

"!" Everyone covered their eyes as a sudden flash of light his them. As quickly as it came, the light vanished. Cautiously, everyone opened their eyes to see…

Joey had disappeared.

"Joey!" Yami had to hold Yugi back from launching forward blindly. A whimper met their ears. Sniffling and holding back tears, Yugi peered behind the couch Joey had sat on moments before. Blonde hair met his eyes and Yugi nearly jumped with joy, "Joey!"

Frightened chocolate-honey eyes flicked up to him as Yugi took a closer look at his friend. The blonde hair was the same and so were the eyes, but they were wider with child-like innocence. His clothes bagged around his significantly smaller form and Yugi believed for a second that he himself had actually grown. Before he realized that Joey had shrunk. Well, scratch that…

Joey had reverted to his child hood.

"Mommy? Daddy?" tears glistened in the honey brown eyes.

Literally.

Phantomworks; how's that for my first puppyshipping story?

**Alice; I must say, it isn't bad.**

Phantomworks: oh and I don't own Coke-a-Cola or its products. Just to make sure everyone knows that.

**Alice: it would be sad if they didn't.**


	2. Chapter 2

Phantomworks; I don't own Yugioh or its characters, only this fanfic.

Chapter 2

"This is all your fault!" Yugi growled –actually _growled_. He must've been spending too much time with the ex-pharaoh to growl like that. The small blonde figure jumped at the harsh tone.

"My fault? May fault? How is it _my_ fault? He drank the serum!" Seto growled back, outraged. To think that his rival would try to pin the blame on him!

"Well you made that- that… thing!" Yugi was at a small loss for words.

"Concoction?" Yami offered.

"Yeah! That vile concoction that turned him into this!" Yugi pointed back to where the small boy was cowering in the smaller of the white-haired duo's arms.

"I only put it in the refrigerator to cool! Whoever gave it to him is the problem. Who gave it to him?" Seto crossed his arms. There was silence now as the two pairs of the doubles looked around the group.

Gasping, they all spoke at once, "Mokuba!"

"What?" blue eyes widened. Why would his brother give the mutt the truth serum?

"You called?" in walked the suspect. "Oh, Seto. I didn't know you were joining us. Want me to get you somethi- ohmygosh! What'sthat?"

Mokuba was a black blur as he nearly talked Ryou. "OMG! He'ssoflippin'cutewhoisheSetowhy'shehereCanwekeephime? ?"

Seto strode over to his little brother and knelt beside him, making them eye-level. "Mokuba, why did you give Wheeler the truth serum?"

"Truth serum? What truth serum?" eyebrows furrowed in confusion.

Taking a slow breath to ease his impatience, Seto tried again, "Remember, I was working on it in my office? It's due to the company tomo-"

"Three months tomorrow." Mokuba corrected.

Growling, but otherwise correction himself, Seto continued, "Three months and I out it in the refrigerator to cool. Did you give it to Joey?"

"Not that I know –wait, was it in a silver can?" Mokuba asked, deep in thought. Seto nodded. "Yeah, I thought it was coke zero. Now I'm wondering why there weren't any funny pictures on it…" he trailed off. "But what does that have to do with this kid? And where's Joey? Did he go home?"

Yugi stepped forward, turning Mokuba to face the kid, "Mokuba, meet kid Joey."

Both pairs of eyes widened, Joey's in fear and Mokuba's in excitement. Quickly, the dark haired teen turned back to his brother, "so we can keep him?"

"No." Seto said right as Yugi said, "Yes."

Amethyst met blue in the glare off of the century.

"You're taking responsibility for this Seto." Yugi ordered.

"Why me? I had nothing to do with this!" Seto objected.

"Yes you did, it's (1) your serum, (2) your brother that gave it to him and (3) your fault. You have to find a way to fix this. Besides, Joey can't go back home and he can't stay with us." Yugi added as Seto opened his mouth to object.

"Why not?" another glare off.

"My house is too small, Bakura would kill him and Duke is your rival. He's bound to get info from Joey about your company."

"Tch, the mutt knows nothing about my company!" Seto crossed his arms defiantly.

"Heh, that's what you think." Yami and Bakura grinned evil smiles at each other.

"… We're going to have to talk about that later. For now –why can't the mutt just go home?" amethyst eyes darkened and his bangs covered his face.

"He just… can't. He'd do better explaining it, so just asked him when you fix this mess." Yugi leaned into the embrace of his darker half.

"And if you don't fix thing, I'm sure that Yugi won't mind if I use my shadow magic." Yami threatened with a smile.

"Or Ryou." Bakura said, grinning madly. Ryou looked away, not denying the claim. The group gout up at that moment and made their way to the front hall. Ryou put Joey down so that he could put on his jacket. Joey immediately attached himself to Yugi's leg with the strength of the average five-year-old (he's 5 by the way).

"No! Don' leave me here! I wanna go home! I wan' my mommy!" the five-year-old bawled. Eyes darkening again, Yugi knelt beside his child friend who then clung to him in a weird hug-like fashion.

"Joey, calm down. Your… your mommy and daddy are on a trip right now. They'll be back soon. You'll have to stay here for now." Yugi calmed the small child.

"W-what… what about Serenity?" the boy wiped his eyes quickly with his sleeve.

"Serenity… she's staying with… Aunt Kyoto." Yugi explained.

"Why? Aunty hates me!" Joey exclaimed, burying his face into Yugi's shoulder.

"Because Kyoto asked to take care of her, but don't worry, Seto and Mokuba will take care of you, okay?"

"But they're strangers! Mommy said to don' talk to strangers!" Joey clung to him as the tri-color haired teen tried to pull away.

"You mean you don't recog –never mind, don't worry Joey… here." Yugi took his cell phone out of his pocket and attached a long cord to it and slid the 'necklace over Joey's head. "You can call me with this. Yami's phone is on the first speed dial. You know Yami?"

The blonde looked up at the double, but shook his head. "No. he looks like you. Is he your onii-chan?"

The word 'onii-chan' tripped Yugi up for a second before he shook his head, "Not really, but wherever he is, I'll be. Okay? So just call him and we can come get you if something bad happens. Okay? So, can you play nicely with Mokuba?"

Nodding, the small boy went to stand beside the pre-teen, grabbing a hold of the bigger's sleeve. Mokuba beamed, his cheeks darkening a little in embarrassment. So this is what it felt like to be a big brother!

"Wait a minute! How come he recognized you but not me?" Yami complained. The rain was starting to thin out a little. Ryou and Bakura took this pause in the weather to make a run for their home.

"Hm? I don't know. Maybe it's that friendship thing Téa always talks about?" Yugi shrugged his coat on.

"I don't believe this! I'm his friend too!" Yami pouted before kneeling beside Joey. The younger of the two his himself slightly behind Mokuba. "Joey, do you know him?"

Eyes flicked in the direction of Yami's pointing finger –Yugi. He shook his head. Yugi's eyes widened in surprise.

"What? But I thought you didn't talk to strangers?" confusion shown in amethyst eyes.

Shrugging, Joey spoke, "Kids don' count."

There was a moment of silence before Yugi exploded.

"I AM NOT A KID! Maybe short, BUT I'M IN HIGH SCHOOL FOR PETE'S SAKE!" Yami had to hold back the enraged height-challenged teen from hurting their child friend.

"Okay, I think it's time to go before it starts raining again. Come on Yugi. Bye Joey, have fun!" Yami waved and cheerfully dragged a colorfully cursing Yugi out the door.

Silence reigned for a while before a small voice broke it.

"He said bad words." Joey pointed at the door and looked up innocently at Mokuba. The older stared at him wide-eyed before bursting out laughing.

"Pft! Hahahahahahahaha! Yes, yes hee-hee he did Joey!" it took a while for the near teen to calm down. "And you know to never say those words, right?"

Joey nodded eagerly.

"Good, let's go get you some better clothes." Mokuba said, taking Joey's small hand. The boy followed him faithfully as he dragged him through the large house. Absently, he heard Seto grumble behind them as he disappeared into his office.

Phantomworks: okay, that's it for this one at the moment.

**Alice; can't you finish at least one story?**

Phantomworks; but I've already finished skater boy, Yugi's diary and Angel's mistake. What more do you want?

**Alice; two words. Bye. Atem.**

Phantomworks; (sighs) I'll work on it.


End file.
